This study will continue the development of electron capture gas chromatography for the quantitative determination of delta- tetrahydrocannabinol and marihuana metabolites in biological samples. The analytical procedures will be evaluated by application to experimental animals with particular emphasis on the pharmacokinetics of cannabinoids in small primates. The purpose of this study is to provide an objective means by which the behavioral and physiological effects of cannabis preparations can be correlated with blood levels of active components.